Different types of packaging are available for the processing, compilation, arrangement and packaging of products such as beverage containers. For instance the articles or containers are combined into portable, relatively handy container units or packs. To combine individual articles into larger packs different ways are known. Beverage containers are combined and packaged into packs comprising four, six or more containers. The generation or manufacturing of such packs is usually unavoidable, because they are the most common type of sale units used for selling beverage containers or bottles made of PET plastic. For transportation several packs are usually combined again and/or assembled in layers and palletized.
In the production of commonly known packs, specific manufacturing steps are required to process the film that is normally used for the shrinking process. These manufacturing steps require a relatively high energy use. The used film causes high costs during manufacturing, provision and handling. After the packs comprising the beverage containers etc. are sold, the used film is not required any longer. Still it causes additional disposal costs. Also, the required machinery like the so-called film-wrapping device and other handling modules, which are required for the manufacturing of these shrink packs, causes high investment costs. Finally, also the provision of the so-called shrinking tunnel requires a relatively high capital investment. In the shrinking tunnel the film, which has been wrapped around the containers, is shrunk around the containers with the use of hot air.
Packs, whereby the containers are held together by at least one strapping, are called strapped packs. These strapped packs do not require the use of shrinking film. The containers are combined and connected into packs with the help of so called strapping strips. The containers, bottles or articles are grouped into formations in continuously or intermittently working strapping devices. These formations are then strapped with one or several strips by a strapping module. Thereby formations of 1×2-arrangements (two containers in a row), 2×2-arrangements (four containers arranged in a squared formation or a diamond shaped formation), 3×2-arrangements, 4×3-arrangements or basically any variable nxm-arrangement can be generated. Stability problems may arise when strapping strips are used for combining containers in packs. Under certain circumstances the containers are not in a stable position to each other. This is mostly due to an unclear assignment of the containers in relation to each other. Usually certain pre-stress forces of the at least one strapping are required to reduce the movement of the containers against each other.
In the beverage industry flexible plastic bottles are preferentially used. Problems may arise due to different internal pressures inside these flexible articles and containers. Many beverage containers are supplemented with carbon dioxide, nitrogen or other gases or substances during filling. The internal pressure of the containers, which are to be connected by a strapping, is not constant but changes depending on different conditions. The internal pressure especially depends on the temperature conditions during the filling process, especially the outer or surrounding temperature. The internal pressure also depends on the concentration of the gas or carbon dioxide in the solution; the time elapsed since the filling and numerous other parameters such as the machine hall temperature, the temperature of the decanted liquid, the season etc. Since the parameters for the strapping process and the pre-stress forces applied during the strapping process have to be set to a specific value, this can easily lead to an excessive or inadequate pre-stress. If the applied pre-stress is too high, the containers can be damaged easily. If the applied pre-stress is too low, the stability of the pack can be impaired. Whether the chosen pre-stress is set correctly for the strapping can essentially only be verified by an extraction and examination of samples. However, this method produces defective containers and packs, which have to be discarded. The parameters for the strapping device have to be set and re-adjusted by an operator.
DE 20 2006 000 215 UI shows a pack that comprises goods and includes a packaging material strapped around the goods. The packaging material is a continuous strip of packaging material. The two ends of the packaging material form an overlapping region. The packing strip is wrapped around the goods, whereby an overlapping region is formed by the two ends. The thus-formed packaging material sections are adhesively attached to the goods by cohesive forces. It is proposed that an adhesive strip is attached on an outer surface of a free end of the strip-shaped packaging material, thereby forming a self-adhesive free end of the packaging material. In this embodiment of a pack, the containers can move in their formation and do not remain stable in the pack.
A pack made from several bottles is described in DE 1 457 489 A. The bottles are held together in the shape of a packaging unit using endless strips. A handle allows the carrying of the package. A further pack arrangement is shown in U.S. Pat. No. 5,775,486 A. Rows of three or six bottles or cans are secured by top-parts made from cardboard and combined into larger packs by means of strapping strips.